Tritanium AL Implants And Instrumentation

ABSTRACT

In some embodiments, the present disclosure relates to a system that includes an insertion tool and a drill guide. The insertion tool includes a body with a distal portion and a distal end. The body has a first engagement feature extending longitudinally along the distal portion and two arms extending longitudinally from the distal end of the body. The drill guide includes two bores and an open faced channel therebetween. The open faced channel includes a second engagement feature slidably engageable with the first engagement feature on the body of the insertion tool. The two bores are adapted for the disposal of a fastener driver tool therethrough.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 17/688,176, filed Mar. 7, 2022, which is a continuation of U.S.patent application Ser. No. 16/775,672, filed Jan. 29, 2020, whichclaims the benefit of the filing date of U.S. Provisional PatentApplication No. 62/799,360, filed Jan. 31, 2019, the disclosures ofwhich are hereby incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

A variety of instruments are often used to advance and place implantsinto an intervertebral space in the spine as part of a spinalreconstructive surgery. When implants are engaged to certaininstruments, a problem may arise in that the implant may be engaged tothe instrument upside down. Such a result may occur because theengagement features on each of the instrument and the implant aresymmetrical about an axis across a width of the implant, so the implantmay be engaged whether it is oriented with a superior side up or aninferior side up. With time, an improper placement of this kind can leadto poor performance of the implant or potentially even failure. Anotherchallenge with implant insertion instruments is that the implant may beunstable or may move relative to instrument while secured to theinstrument. This may occur due to a lack of a rotational restraintincorporated into the engagement features on the instrument.

Further, drill guides are often used to aid in the insertion of screwsthrough intervertebral implants to secure the implant to adjacentvertebral bodies. However, such drill guides are typically standaloneinstruments. As a result, a surgeon requires one instrument to positionthe implant in the surgical space and another instrument to aid in theseating of screws through the implant and into the bone. This problem ofexcess instrumentation is exacerbated by the need to have differentsizes of insertion instruments and drill guides available, which demandseven more instrumentation. Moreover, the more instruments that areutilized, the more instruments ultimately need to be sterilized beforeadditional surgeries can be conducted.

Existing challenges extend to stability of the spinal implantsthemselves, even when properly placed in an intervertebral disc space.In some instances, forces acting on the implant may cause screws to backout of their positions in the implanted implant. This may lead to poorperformance or failure of the implant. Other problems may includelimitations on the possible orientations of the implant when insertedinto the intervertebral space.

Thus, there is a need to simplify methods of inserting an implant intothe spine and to reduce the risk of implant failure after completion ofsurgery.

BRIEF SUMMARY OF THE INVENTION

In one aspect, the present disclosure relates to a system that includesan insertion tool and a drill guide. In one embodiment, the insertiontool includes a body with a distal portion and a distal end, the bodyincluding a first engagement feature extending longitudinally along thedistal portion and two arms extending longitudinally from the distal endof the body. The drill guide includes two bores and an open facedchannel therebetween, the open faced channel including a secondengagement feature slidably engageable with the first engagement featureon the body of the insertion tool. The two bores are adapted for thedisposal of a fastener driver tool therethrough.

In some embodiments, the insertion tool may include three prongs thatextend longitudinally from the distal end. In some embodiments, thethree prongs may include a first prong, a second prong and a thirdprong. The first prong and the second prong may have equal and oppositeshapes and the third prong may have a shape different from each of thefirst prong and the second prong. In some embodiments, the insertiontool may have a cross-sectional shape distal to the distal end thatincludes the first, second and third prongs. The cross-sectional shapemay be asymmetrical about a first axis across a width of the insertiontool, the first axis parallel to an axis passing through a free end ofthe first prong and a free end of the second prong.

In some embodiments where the insertion tool includes three prongs, thethree prongs may include a first prong and a second prong that are afirst length and a third prong that is a second length, the first lengthlonger than the second length. In some embodiments, the first prong mayextend to a first free end and the second prong may extend to a secondfree end, each of the first free end and the second free end including aprotrusion thereon.

In some embodiments, the two prongs may be biased inward toward oneanother. In some embodiments, the first engagement feature may be a pairof slots on opposite surfaces of the body of the insertion tool. Tocomplement the slots, the second engagement feature may be a pair ofrails that face one another. Each of the rails is disposable within arespective slot of the body.

In some embodiments, the insertion tool may include an actuatable buttonon the distal portion of the body. The actuatable button may be biasedto protrude relative to the body. In some embodiments, the drill guidemay be adapted to slide over the actuatable button while one of thefirst engagement feature and the second engagement feature is disposedin the other. With the aforementioned features, the drill guide issecured to the insertion tool when positioned in between the actuatablebutton and the distal end of the body. In some embodiments, the firstengagement feature may have a length that extends from a proximal end toa distal end. The distal end of the first engagement feature may beseparated from the distal end of the body. In some examples, the bodymay be cannulated and includes a slidable element disposed therein, theinsertion tool being actuatable to advance and retract the slidableelement. In some embodiments, the insertion tool may be actuatable tocause forward advancement of the slidable element. Such advancementincreasing a spacing between the first arm and the second arm.

In another aspect, the present disclosure relates to an insertion tool.In one embodiment, an insertion tool includes a body with an outershaft, first and second arms, a pin and an inner shaft. The outer shafthas a length extending from a proximal end to a distal end. The firstarm, second arm and pin each extend from the distal end. The distal endhas a cross-sectional shape that includes the first arm, the second armand the pin. The cross-sectional shape is asymmetric about a first axisacross a width of the body through its center. The first axis isparallel to a second axis through a free end of the first arm and a freeend of the second arm. The inner shaft is disposed within and movablerelative to the outer shaft of the body. When the inner shaft moves intocontact with the first arm and the second arm, the inner shaft increasesa distance between the first arm and the second arm.

In some embodiments, the insertion tool may also include a lever armattached to the body. The lever arm may be rotatable relative to thebody through mechanical coupling of the lever arm to the inner shaftsuch that actuation of the lever arm causes the inner shaft to move. Insome embodiments, the insertion tool may include a lock button attachedto the body. The lock button may be adjustable from a closed position toan open position. In the closed position, the lever arm is locked in afixed position and in the open position, the lever arm is rotatableabout an axis through its connection point with the body. In someembodiments, the lock button may be biased in the closed position. Insome embodiments, the first arm and the second arm may have a firstshape and the pin may have a second shape, where the first shape isdifferent from the second shape. In some embodiments, the first arm andthe second arm may be a first length and the pin may be a second length,the first length being longer than the second length. In someembodiments, each of the first arm and the second arm may become largerin size toward their respective free ends such that outward facingsurfaces of each arm that face away from each other at the free endsprotrude relative to a remainder of each arm.

In another aspect, the present disclosure relates to an intervertebralimplant. In one embodiment, the intervertebral implant includes a body,a fastener and a locking element. The body includes a plurality ofopenings therein. Each of the plurality of openings is accessible from asingle side of the body. The fastener is disposed in a first opening ofthe plurality of openings and the locking element is disposed in asecond opening of the plurality of openings. The locking elementincludes a head, a flexible base abutting the head and a shaft extendingfrom the flexible base. The flexible base and the shaft extend along alongitudinal axis. The flexible base is movable from a first position toa second position. In the first position, the flexible base is securedto the body and has a first perimeter. In between the first position andthe second position, a portion of the flexible base is deformed so thatthe flexible base has a second perimeter smaller than the firstperimeter, the first perimeter and the second perimeter measured at thesame axial location on the flexible base. The locking element may bemovable between a first orientation relative to the body that blocks thefirst opening and a second orientation relative to the body that doesnot block the first opening.

In some embodiments, the flexible base may include a flexible bar thatextends from a remainder of the flexible base to a free end such thatthe flexible bar is separated from the remainder of the flexible base bya space. In some embodiments, the flexible bar may include a protrusionthat extends outward adjacent to the free end. In some embodiments, thesingle side of the body may include a first recessed surface sized toreceive the head of the locking element and a second recessed surfacethat is recessed relative to the first recessed surface. The secondrecess may be sized to receive the flexible base. In some embodiments,the second recessed surface may include a perimeter defined by a firstportion with a first radial dimension and a second portion with a secondradial dimension smaller than the first radial dimension. The secondportion may be interrupted by a first groove and a second groove spacedfrom one another along a partially circumferential length of the secondportion. In some embodiments, when the locking element is disposed inthe implant such that the head is disposed on the first recessedsurface, the locking element may be rotatable such that the protrusionof the flexible bar is disposable in the first groove and in the secondgroove. In some embodiments, when the protrusion is disposed in thefirst groove, a ridge on the base may abut a first end of the firstportion of the perimeter of the second recessed surface. Similarly, whenthe protrusion is disposed in the second groove, the ridge on the basemay abut a second end of the first portion of the perimeter of thesecond recessed surface.

In some embodiments, the remainder of the flexible base separate fromthe flexible bar may include a longitudinal ridge. In some embodiments,the flexible bar may include a protrusion that extends outward adjacentto the free end and the remainder of the flexible base may include alongitudinal ridge that is positioned opposite the protrusion on asurface of the base. In some embodiments, the space in the flexible baseis L-shaped. In some embodiments, the shaft may be a pair of flexibleprongs. In some embodiments, the locking element may be locatedequidistant from upper and lower surfaces of the implant. In someembodiments, the intervertebral implant may include a second lockingelement that is the same as the first locking element. In someembodiments, the single side of the body may be an anterior side. Insome embodiments, the body of the implant may be monolithic.

In one embodiment, an intervertebral implant includes a body, a fastenerand a locking element. The body has a plurality of openings therein,each of the plurality of openings being accessible from a first side ofthe body. The first side of the body has a first recessed surface and asecond recessed surface. The fastener is disposed in a first opening ofthe plurality of openings. The locking element is disposed in a secondopening of the plurality of openings, the second opening being locatedentirely within the second recessed surface. The locking elementincludes a head, a flexible base abutting the head, and a shaftextending from the flexible base. The flexible base includes a firstpart and a second part separated from the first part by a third opening.The first part extends to a free end and has a protrusion, while thesecond part includes a ridge. The shaft extends from the flexible base,and the shaft and the flexible base extend along a longitudinal axis.The flexible base is movable from a first position to a second positionsuch that in the first position, the protrusion is engaged with a groovedefined by a boundary between the first recessed surface and the secondrecessed surface and the ridge abuts a radially oriented edge of thesecond recessed surface. In the second position, the first part of theflexible base is compressed from a neutral position and is outside ofthe groove. The locking element is movable between a first orientationrelative to the body that blocks the first opening and a secondorientation relative to the body that does not block the first opening.

In another aspect, the present disclosure relates to a kit. In oneembodiment, the kit includes an insertion tool, a guide structure and aninterbody implant. The insertion tool has a body with an end and aplurality of prongs that extend from the end. The guide structure hastwo bores sized for the placement of fastener driver tool therethrough.The guide structure is engageable with the insertion tool. The interbodyimplant has two openings on a single side. Each of the two openings issized to receive at least one of the plurality of prongs of theinsertion tool. The insertion tool is adapted to engage with the guidestructure and the interbody implant at the same time.

In some embodiments, the plurality of prongs may include three prongs ofwhich two are receivable in a first of the two openings and one isreceivable in a second of the two openings. In some embodiments, theinsertion tool may include a surface with a longitudinally extendingslot and the guide structure may include a longitudinally extendingrail. The rail may be disposable in the slot to engage the guidestructure with the insertion tool.

In one embodiment, a kit includes an insertion tool, an interbodyimplant and a graft clip. The insertion tool includes a body with an endand a plurality of prongs that extend from the end. The interbodyimplant has two openings on a single side, each of the two openingssized to receive at least one of the plurality of prongs of theinsertion tool. The graft clip is engageable with the body and isadapted to cover opposing surfaces of the body and the implant when theimplant is engaged to the insertion tool. The graft clip includes twoarms that are biased toward one another at a distal end of the graftclip.

In some embodiments, each arm may include an outward facing surface witha protrusion thereon.

In another aspect, the present disclosure relates to a method ofimplanting an interbody implant into a mammalian spine. In oneembodiment, the method involves steps including: advancing an end of aninsertion tool into an intervertebral implant such that a pair of prongsextending from a distal end of a body of the insertion tool pass througha first opening in the implant and a pin extending from the distal endpasses through a second opening in the implant; sliding a drill guideonto the insertion tool and over an actuatable element on the body bydisplacing the actuatable element from a neutral position; and securingthe drill guide to the insertion tool through sliding engagement betweena first engagement feature on the drill guide and a second engagementfeature on the insertion tool along with advancement of the drill guidedistally past the actuatable element so that the actuatable elementreturns to the neutral position and prevents drill guide from slidingaxially in a proximal direction.

In some embodiments, the method may include actuating a control on theinsertion tool to advance an inner shaft within the body until the innershaft is in between the pair of prongs, the advancement of the innershaft preventing laterally outward facing protrusions on each prong fromretreating into the first opening. In some embodiments, actuating thecontrol may include rotating a lever arm attached to the body to causethe inner shaft to advance relative to an outer shaft of the body. Insome embodiments, the method includes actuating a detent mechanism inthe body to unlock the lever arm and allow rotation of the lever arm.

In some embodiments, sliding of the drill guide over the actuatableelement may involve sliding the drill guide over a button on the bodyadjacent to the distal end, the button depressing when the drill guideis over the button and the button rising when the drill guide is sliddistally past the button, the button thereby preventing proximalmovement of the drill guide to hold the drill guide in place on theinsertion tool.

In another aspect, the present disclosure relates to a method of lockingfasteners disposed in an intervertebral implant. In one embodiment, themethod involves steps including: inserting an intervertebral implantinto an intervertebral disc space between adjacent vertebral bodies in apatient; rotatably advancing a fastener through an opening in theintervertebral implant into a vertebral body adjacent to theintervertebral disc space so that the fastener anchors into thevertebral body; and rotating a locking element disposed in the implantfrom a first position to a second position, the locking elementincluding a flexible base with an engagement feature that bends todisengage from the first position, wherein in the first position, theopening is unobstructed by the locking element and in the secondposition, the opening is obstructed by the locking element to preventback out of the fastener.

In some embodiments, rotation of the locking element may involvedisengaging the protrusion from a first groove in a recessed surface ofthe intervertebral implant. In some embodiments, rotation of the lockingelement may be limited to a rotational range extending between andincluding the first position and the second position. In someembodiments, the rotation of the locking element may be limited by aridge of the locking element abutting a first outer edge or a secondouter edge of a recessed surface defining a volume within which thelocking element is partially disposed, the first outer edge or thesecond outer edge blocking further rotation of the locking element inone rotational direction. In some embodiments, the rotation of theflexible base from the first position or the second position todisengage the locking element from the first position or the secondposition may cause a cross-sectional size of the locking element todecrease.

In some embodiments, the method may include rotation of two lockingelements, each locking element rotated in a clockwise direction toobstruct the opening and a second opening. In some embodiments, themethod may include inserting the locking element into the implantthrough a second opening in the implant, the locking element including aflexible shaft that flexes inward during insertion and expands outwardonce fully inserted to limit axial movement of the locking element.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be better understood on reading thefollowing detailed description of non-limiting embodiments thereof, andon examining the accompanying drawings, in which:

FIG. 1 is a perspective view of an implant insertion system with anintervertebral implant attached according to one embodiment of thedisclosure.

FIG. 2 is a top view of an insertion tool of the system of FIG. 1 .

FIG. 3 is an exploded view of the insertion tool of FIG. 2 .

FIGS. 4 and 5 are close up partial views of a distal end of theinsertion tool of FIG. 2 .

FIGS. 6-8 are various views of a drill guide of the system of FIG. 1 .

FIGS. 9 and 10 are bottom and top perspective views, respectively, of anintervertebral implant according to one embodiment of the disclosure.

FIGS. 11-13 are various sectional views of the intervertebral implant ofFIG. 9 .

FIG. 14 is a sectional view of the intervertebral implant of FIG. 9without locking elements and fasteners.

FIGS. 15-18 are various views of a locking element of the intervertebralimplant of FIG. 8 .

FIGS. 19A-19B are side and perspective views of an implant according toanother embodiment of the disclosure.

FIG. 20 is a side view of an intervertebral implant according to anotherembodiment of the disclosure.

FIG. 21 is a side view of an intervertebral implant according to anotherembodiment of the disclosure.

FIGS. 22A and 22B are close up partial views of the intervertebralimplant of FIG. 21 .

FIGS. 23 and 24 are perspective and side views, respectively, of a graftclip according to another embodiment of the disclosure.

FIGS. 25-30 are various views of an intervertebral implant according toanother embodiment of the disclosure.

FIGS. 31-36 are various views of an intervertebral implant according toanother embodiment of the disclosure.

FIGS. 37-38 are partial side and close up views, respectively, of aninsertion tool and an intervertebral implant in a step of a method ofimplantation according to another embodiment of the disclosure.

FIG. 39 is a partial close up sectional view of the insertion tool ofFIG. 37 in another step of the method.

FIGS. 40-42 are various views of the insertion tool and theintervertebral implant of FIG. 37 in another step of the method.

FIG. 43 is a perspective view of the insertion tool of FIG. 37 with adrill guide engaged in another step of the method.

FIGS. 44 and 45 are close up perspective and sectional views,respectively, of the insertion tool and the drill guide of FIG. 42according to another step of the method.

FIGS. 46-49 are side views of an intervertebral implant in steps of amethod of locking fasteners of the intervertebral implant according toanother embodiment of the disclosure.

FIGS. 50-51 are close up partial side views of an intervertebral implantin steps of a method of locking fasteners of the intervertebral implantaccording to another embodiment of the disclosure.

FIGS. 52-53 are close up partial side views of an intervertebral implantin steps of a method of locking fasteners of the intervertebral implantaccording to another embodiment of the disclosure.

FIGS. 54-56 are various views of an insertion tool and graft clip insteps of a method of securing the graft clip to the insertion toolaccording to another embodiment of the disclosure.

DETAILED DESCRIPTION

The present disclosure generally relates to instruments and implantsused to repair and reconstruct a mammalian spine. Instruments describedinclude an insertion tool, a drill guide engageable with the insertiontool, and a graft clip, among others. These instruments are used toimprove methods of placing an intervertebral implant within anintervertebral space in a reconstructive surgery. Further, variousimplants used with such instruments are also described herein. Oneexample of an implant insertion system 5 is shown in FIG. 1 and includesan insertion tool 10 and a drill guide 60. In the illustrated system, anintervertebral implant 700 is secured to the insertion tool. Thesecomponents improve the ability of a user to engage an implant with aninstrument and also improve the ability of the user to properly securethe implant in the correct position within a body of a patient. The useof the term “user” herein should be construed broadly to mean the personor machine (e.g., robot) performing the surgery. This could be, forexample, a surgeon.

It should be appreciated that although specific examples providedthroughout the disclosure reference spinal surgery and methods involvingantero-lateral or lateral approaches to the spine, the principles setforth herein are contemplated for application in other surgicalapproaches or in other areas of the body where similar access isrequired and/or where implants with a similar structure are implanted.

As used herein, the terms “proximal” and “distal,” when used inreference to an insertion tool, a related instrument, or an implant, areto be taken as relative to the user of the insertion tool. “Proximal” isto be understood as closer to the user and “distal” is to be understoodas farther away from the user.

In one aspect, the present disclosure relates to an insertion toolstructure, as shown in FIGS. 2 and 3 . Insertion tool 10 includes ahandle 30 and a body in the form of an outer shaft 11.

Insertion tool 10 includes a variety of features and components, asshown in the exploded view of FIG. 3 . Beginning with handle 30, anopening that is continuous with enclosed passage 16 is included withinthe handle for disposal of an actuation mechanism. The actuationmechanism is connected to an inner shaft 13 disposed in outer shaft 11and is described in greater detail below. The opening within the handleis enclosed in part, as shown, for example, in FIGS. 37 and 39 . Theactuation mechanism includes a lever arm 34 and an internal link 32connected to one another via pin 33. Lever arm 34 is connected to handle30 via pin 35. Through the pin connection, lever arm 34 is pivotableabout an axis through pin 35 as shown in FIGS. 37, 39 and 40 anddescribed in greater detail below. On a bottom surface of handle 30opposite the lever arm is a lock button 45, which is secured to handle30 via a pin 46 that is threaded into a corresponding thread 44 in aball detent 40, disposed internally within the handle. These featuresare best shown in FIG. 39 . Ball detent 40 is disposed within handle 30such that it lies immediately proximal to an internally disposed portionof lever arm 34, again, shown in FIG. 39 . Proximal to ball detent 40 isa spring 48 and then an end cap 49 closing the enclosed channel of thehandle at an end of insertion tool 10. Through this assembly, balldetent is axially adjustable from a biased position abutting the leverarm to a retracted position, with spring compressed, that is spacedapart from the lever arm. Through operative connection of detent 40 withlock button 45, lock button 45 is actuatable to retract detent 40.

Turning to the leading end of insertion tool 10 that extends from handle30, outer shaft 11 is axially aligned with handle 30 and is cannulatedso that inner shaft 13 is disposed in an enclosed passage 16 therein.Inner shaft 13 disposed in outer shaft 11 is shown in FIG. 37 , forexample. Inner shaft 13 is operatively connected to lever arm via pin31, which connects inner shaft 13 with internal link 32. In this manner,the operative connection is such that rotation of lever arm 34 about theaxis through pin 35 causes inner shaft 13 to move axially eitherdistally or proximally. At a distal portion 17 of outer shaft 11, outershaft is of a larger size and includes a button 20 secured thereto viasprings 22A-B underneath. In some examples, as shown in FIGS. 3 and 45 ,a plug 24 is positioned on an opposite side of springs 22A-B relative tobutton 20 to fully enclose the springs. Without load applied to button20, button 20 is biased in a raised position relative to a surface ofouter shaft 11, as shown in FIG. 42 , for example. However, button 20may be depressed with the application of forces thereon, therebycompressing springs 22A-B. Distal portion 17 of outer shaft 11 alsoincludes a pair of opposing lateral sides, each having an engagementfeature in the form of a longitudinally extending slot 26A, 26B therein.As described in greater detail below, these slots are sized for thedisposal of a drill guide 60 therein.

Outer shaft 11 extends to a distal end 12, which is also the end ofdistal portion 17. From distal end 12, as shown in FIGS. 4 and 5 , apair of arms 14A, 14B that mirror one another extend longitudinally.Arms 14A, 14B are positioned on insertion tool 10 such that enclosedpassageway 16 is located immediately in between each arm 14A, 14B. Thus,in the event that inner shaft 13 is advanced distal to distal end 12,inner shaft 13 contacts inside faces of arms 14A, 14B. Each arm 14A, 14Bextends to a free end remote from distal end 12 and has a generallyuniform shape over most of its length. As shown in FIGS. 4 and 5 , eacharm has a protrusion 15A, 15B at a respective free end. The protrusionsface laterally outward such that surfaces of each arm that face theother arm do not have the protrusion feature. Each arm 14A, 14B isbiased slightly inward so that any increase in the distance separatingthe arms is only preserved while force is applied. Otherwise, the armsreturn to their biased, or neutral, position.

Offset from a first center axis 51 across the free ends of each arm is apin 18. As shown in FIGS. 4 and 5 , pin 18 also extends from distal end12 of outer shaft 11. A free end of pin 18 is closer to distal end 12than the free ends of respective arms 14A, 14B. Pin 18 has a generallyuniform and nearly rectangular cross-section over its length althoughvariations in its shape are contemplated to suit a corresponding openingin an implant to be engaged by the insertion tool. Pin 18 is centered ona second center axis 52 along a depth of outer shaft 11. Further, arms14A, 14B are symmetrical about center axis 52. As shown in FIG. 4 ,although a combination of the arms and pin are symmetrical about centeraxis 52, such combination is not symmetrical about an axis perpendicularto center axis 52, such as center axis 51. Indeed, there is nocounterpart to pin 18 extending from distal end 12 of insertion tool 10.In this manner, insertion tool 10 has engagement features that arepositioned for directional or one-way engagement with an implant.

The insertion tool may be varied in many ways. For example, theinsertion tool may be various sizes to accommodate different sizes ofimplants. Indeed, it is contemplated that the insertion tool may have asize of 10/12, 14/16, 18/20 or 22/24 mm. Each of these sizes mayaccommodate attachment to at least two different implant heights. Inother examples, the pin may be adjacent to an upper surface of theinsertion tool instead of being adjacent to a bottom surface, while thearms remain at the same depth on the body of the insertion tool. Thismay be desirable where the implants intended to be used are smaller. Inother examples, four or more engagement features may be used. Forexample, there may be four prongs and a single pin where each of thefour prongs is insertable into a single opening in an implant or intotwo separate, parallel openings.

In another aspect, the present disclosure relates to a drill guide. Oneembodiment of drill guide 60 is shown in FIGS. 6-8 . Drill guide 60includes a central body 62 with a pair of bores 61A, 61B positioned onlateral sides of central body 62. Each bore 61A, 61B includes an opening68A, 68B, respectively, sized to dispose a driver tool for the fastenertherethrough. As shown in each of FIGS. 6-8 , the bores are oriented sothat an axis through each bore is angled toward a centerline of thedrill guide in a direction toward the leading end. A leading end of eachbore terminates on a leading end face 74A, 74B of drill guide 60. At anend opposite leading end, central body includes trailing end faces 72A,72B. As shown in FIGS. 7 and 8 , the trailing end faces are separated byan inwardly recessed edge 75. Edge 75 defines an open space over centralbody 62 sized to allow an end of button 20 to fit within the open spacewhen drill guide 60 is in a secured position with respect to insertiontool 10, described in greater detail in the methods of use of thedisclosure.

As shown in FIG. 6 , central body 62 includes a central channel 63 alongits length, extending from trailing end faces 72A-B to leading end faces74A-B. Dimensions of channel 63 are defined by side surfaces 66A, 66Band bridging surface 65. Side surfaces 66A-B are generally planar tomatch an outer surface of outer shaft 11 and, similarly, bridgingsurface 65 has a slight arcuate shape to match an upper surface of outershaft 11. Of course, in variations where a shape of outer shaft 11 isdifferent from that shown, a shape of the channel may vary accordinglyto match such shape. Protruding from each side surface 66A, 66B arelongitudinally extending engagement features in the form of rails 64A,64B. The rails extend over a portion of the length of the channel andare positioned away from upper and lower ends of the side surfaces, asshown in FIGS. 6 and 8 . Alternatively, the rails may extend over agreater or lesser portion of the length of the drill guide. Each railhas a generally rectangular sectional shape with beveled corners, thesize and shape of each rail tailored for engagement with a correspondingslot 26A, 26B on a side surface of the outer shaft 11. In this manner,the shape of the rails, and indeed the slots, may vary from thatdescribed and shown. Further, the rail and slot combination may besubstituted with other complementary engagement features. More detailregarding the function of the rails is provided in the description ofthe method of using the drill guide elsewhere in the application.

The drill guide may be varied in many ways. For example, as with theinsertion tool, the drill guide may be sized for particular implantsizes. Because the drill guide is easily attached to the insertion tool,described in detail in the methods of the disclosure, these size optionsrender it much easier for the user to obtain instrumentation of aparticular size that is suitable for a surgery without requiringmultiple standalone instruments that have the particular dimensionsnecessary. In other examples, the rail feature on the drill guide may besubstituted with another engagement feature. For instance, the sidesurface may have a longitudinally extending slot to receive a rail onthe insertion tool. A shape of the rail and slot counterpart may alsovary.

In another aspect, the present disclosure relates to an intervertebralimplant. The intervertebral implant may be adapted for use in ananterior lumbar interbody fusion (ALIF) procedure. It may be used as aninterbody with no fasteners or as a standalone device with fasteners.

One embodiment of intervertebral implant 100 is shown in FIGS. 9-13 . InFIGS. 9 and 10 , an overall view of the implant is shown includingsuperior surface 110, lateral side surfaces 106, 108, anterior surface102 and posterior surface 104. Through superior surface 110 to aninferior surface 112 is a graft window 116. Each of superior surface 110and inferior surface 112 include fins 118. And, superior and inferiorsurfaces 110, 112 taper toward one another from the anterior side to theposterior side such that the implant is narrower at the posterior side.In some embodiments, a body of implant 100 is monolithic.

Implant 100 includes a series of openings for disposal of fasteners andlocking elements. Through anterior surface 102 are three openings 131,134, 137 at approximately equal spacing with respect to one another.Openings 131, 137 are located on opposite sides of the implant and areaxially aligned in the same manner such that the openings extend fromthe anterior surface to the inferior surface. Opening 134, positionedmid-way in between openings 131, 137, extends from the anterior surfaceto a combination of the superior surface and an interior surface withinthe graft window, best shown in FIG. 10 . In this manner, an alignmentof opening 134 is transverse to an alignment of each of openings 131,137. Each opening has a linear alignment so that fasteners aredisposable therein. Fasteners 121, 124, 127 are disposed in openings131, 134, 137, respectively. Each fastener includes engagement featuresto drive the fastener into place. For example, as shown in FIG. 11 ,fastener 124 includes a hex drive 125 and an internal thread 126. Ofcourse, these features may vary to suit the use of drivers with othertip shapes. Openings 131, 134, 137 have rounded surfaces on the anteriorside of the implant so that each fastener may be angulated up to fivedegrees from a nominal alignment, thereby providing flexibility for theuser.

Within opening 134 is an additional opening 136 extending from withinopening 134 to an internal surface of the implant, as shown in FIGS. 10and 13 . Opening 136 is sized so that arms of an insertion tool arepositionable therethrough when slightly compressed. Also centered onanterior face but separate from openings 134, 136 is opening 135.Opening 135 is an oblong shape as shown in FIGS. 9 and 13 and extendspartially into implant 100. Opening 135 is sized so that a pin of aninsertion tool is disposable therein. In an alternative configuration,the opening for the pin may extend from the anterior surface through tothe interior surface of the implant defining the graft window.Additionally, the opening for the pin may begin from within opening 134or separately from outside of it. The combination of openings 135, 136defines an asymmetrical surface on implant 100 through the offsetposition of opening 135. Thus, the implant is designed so that theinsertion tool may only be inserted into the implant in one orientation.In this manner, the engagement between the insertion tool and implant isdirectional. If the insertion tool is upside down, pin 18 will encounteranterior surface 102 upon contact with implant and will preventsecurement of the insertion tool with the implant. Further to thedirectional engagement feature, one advantage of the implant is thatonce the implant is secured to the insertion tool, the implant on theend of the tool may be inserted into an intervertebral space either withthe superior surface of the implant or the inferior surface of theimplant facing upward. In either orientation, the same functionality isprovided. With regard to securement between insertion tool 10 shown inFIGS. 2-5 and an implant, it should be appreciated that implant 700 isshaped particularly for engagement by arms 14A, 14B and pin 18 ofinsertion tool 10. Implant 700 is described in greater detail below.

In between openings 131, 134 is another opening 181A shown in FIGS. 12and 14 that extends from anterior surface 102 to an interior surface ofgraft window 116. Opening includes a lip 109A near the graft window endof the opening. A second opening 181B of the same shape is locatedbetween openings 134, 137. Disposed within each of these openings is alocking element 150A, 150B. Each locking element is sized to fit fullyand securely within the designated openings within the implant, as shownfor example, in FIG. 12 . The details of the locking elements will nowbe described. For clarity, only the structure of locking element 150A isdescribed, but it should be appreciated that locking element 150B sharesthe same structural features.

As shown in FIGS. 15-18 , locking element 150A includes a head 152A, aflexible base 154A that abuts head 152A, and a shaft 156A that extendsfrom base 154A. Head 152A is oblong and has a width greater than adiameter of both base 154A and shaft 156A. Base 154A is cylindrical witha space 165A formed therein. Space 165A is L-shaped and divides base154A into a main portion and a flexible bar 161A. Flexible bar 161A is acantilever that extends from an end of base 154A that abuts shaft 156Ato a free end facing head 152A, as shown in FIGS. 16 and 18 . The exactshape of space 165A may vary provided that the flexible bar extends to afree end. The geometry of flexible bar 161A and its space from the mainportion of base 154A causes flexible bar 161A to deform when subject toa threshold load. In a neutral position without loads applied, an insidesurface of flexible bar 161A is generally parallel to an inside surfaceon the main portion of the locking element, as shown in FIG. 15 .Extending outwardly from a rounded surface of flexible bar 161A isprotrusion 163A positioned at the free end of flexible bar 161A. Also onbase 154A is ridge 162A that protrudes from an outer surface of base154A. As shown in FIG. 18 , ridge 162A is directly opposite protrusion163A and, as shown in FIG. 16 , ridge 162A extends over a length of base154A traversing a distance between head 152A and shaft 156A.

Turning to shaft 156A, the shaft includes two prongs 158A, 159A that areseparated by slit 171A. Each prong is approximately equal in size andincludes a radial ridge 167A, 169A that defines at wider portion near adistal tip of locking element 150A, along with a tapered distal end168A. When disposed in implant 100, radial ridge 167A sits above lip109A to hold locking element 150A toward anterior side in an axialdirection. Each prong 158A, 159A is biased in the manner shown so thateach one is pushed closer to the other to place locking element 150Athrough opening 181A. Thus, when in position over lip 109A, an inwardforce on the prongs is required to pull the locking element anteriorly.Between base 154A and radial ridge 167A, shaft 156A is generallycylindrical with the exception of the slit between prongs 158A, 159A.

Returning to the main structure of intervertebral implant 100, from ananterior side of implant 100 through anterior surface 102 are geometricfeatures surrounding openings for the locking elements that support thedisposal, adjustability and securement of the locking elements in theimplant. To describe these features reference is made to FIG. 14 andopening 181A that receives locking element 150A. However, again, itshould be appreciated that opening 181B has the same features forreceipt of locking element 150B.

Surrounding opening 181A are a pair of stepped surfaces that areprogressively closer to anterior surface 102. Immediately surroundingopening 181A is second recessed surface 144A and surrounding the secondrecessed surface is first recessed surface 142A.

Second recessed surface 144A has an inner edge defined by opening 181Awhile its outer edge is a perimeter that abuts a step to first recessedsurface 142A. In particular, the perimeter is divided into two segmentsseparated by a first location 145A and a second location 146A. A firstsegment 147A of the edge that extends between the first location and thesecond location is curved, has a first radius along its length and spansmore than half of a circumferential distance around opening 181A. Alongthe length of first segment 147A, the edge deviates from the firstradius at two, spaced locations 148A, 149A. At each of these locations,the edge is recessed away from opening 181A, as shown in FIG. 14 .Although the edge has a concave rounded edge at each recess 148A, 149A,it is contemplated that such shape may be varied to accommodate matchingsurface features on the locking element used with implant 100. A secondsegment 143A extending between ends of the first segment at first andsecond locations 145A, 146A is curved and has a second radius along itslength. As shown in FIG. 14 , the second radius is greater than thefirst radius.

An inside edge of first recessed surface 142A abuts the edge of secondrecessed surface, again shown in FIG. 14 . An outer edge of firstrecessed surface has two separate segments opposed from one another,each having the same radius and abutting a step to anterior surface 102.The segments are separated by openings 131, 134 for the fasteners in theimplant. Thus, the edges that bridge each of the opposed segments aredefined by the radius of openings 131, 134. The recessed surfaces aredimensioned and define a volume in the implant such that portions of thelocking element are disposable therein. In particular, at least part ofbase 154A is disposable in a volume defined by second recessed surface144A and at least part of head 152A is disposable in a volume defined byfirst recessed surface 142A. More detail on the interaction between thelocking element and the implant surfaces is provided in the descriptionof the method.

Another embodiment of an intervertebral implant is shown in FIGS. 19A-B.Unless otherwise stated, like reference numerals refer to like elementsof above-described intervertebral implant 100, but within the 700-seriesof numbers. Implant 700 includes locking elements 750A, 750B that arethe same as locking elements 150A, 150B. Further, implant 700 surfacefeatures beneath the locking elements (not shown) are the same as thosedescribed for implant 100, thereby providing the same structure to movelocking elements between unlocked and locked positions. However, incontrast to implant 100, opening 735 that is sized for disposal of pin18 therein is adjacent to inferior surface 712, unlike implant 100. Inthis manner, openings 735, 736 are sized and positioned in implant 700for disposal and engagement by pin 18 and arms 14A, 14B of insertiontool 10, respectively, as the pin is positioned to match the openingclosest to the inferior surface of the implant. The complementary natureof the features of insertion tool 10 and implant 700 is shown through acomparison of FIG. 4 and FIG. 19A, for example. In FIGS. 19A-B, opening735 is separate from opening 734. However, in alternatives such as thosenoted above, the openings may also commence from a common opening in theimplant.

In another embodiment, implant 200 is shown in FIG. 20 . Unlessotherwise stated, like reference numerals refer to like elements ofabove-described intervertebral implant 100, but within the 200-series ofnumbers. Anterior surface 202 includes a recessed surface (not shown)between openings 231, 234 and 234, 237, respectively. Each recess isstepped below anterior surface 202. With reference to locking element250A as representative, and the recessed surface associated with lockingelement 250A, the recessed surface has an arcuate perimeter with a firstradius that measures about the same as a long dimension of a head 252Aof locking element 250A. Further, one segment of the edge of therecessed surface includes two separate inward bulge features that appearas bumps on the arcuate path of the recessed surface edge. These bulgesare sized to fit a pair of recessed grooves 272A, 273A on one side ofhead 252A of locking element 250A, as shown in FIG. 20 . The abovedescribed structure allows locking element 250A to move between twopositions, one where both grooves 272A, 273A are locked with respectivebulges in the recessed surface and another where one groove is locked.In FIG. 20 , locking element 250B is shown with one groove 273B lockedto a bulge in the recess on the surface of the implant. In eitherposition, the locking element is rotationally fixed relative to theimplant.

In yet another embodiment, implant 300 is shown in FIGS. 21, 22A and22B. Unless otherwise stated, like reference numerals refer to likeelements of above-described intervertebral implant 100, but within the300-series of numbers. Implant 300 includes locking elements 350A, 350B.With reference to locking element 350A as representative, lockingelement 350A includes head 352A having an open channel 365A on one side,as shown in FIGS. 21 and 22A. The open channel separates a main body ofthe head from flexible bar 361A, which extends from the main body ofhead 352A to a free end. Adjacent the free end of flexible bar 361A isprotrusion 363A that protrudes outward away from a remainder of head352A. Flexible bar 361A is shaped and positioned so that when subject toloads, flexible bar 361A deforms to move closer to the main body of head352A. Shaft 356A abuts head 352A, as shown in FIG. 22A. An innerprotrusion 362A extends radially from shaft 356A in a direction facingflexible bar 361A, again shown in FIG. 22A. When locking element 350A isdisposed in implant 300, inner protrusion 362A fits within acorresponding recess within implant 300 in a manner similar to ridge162A of locking element 150A. And, although flexible bar 361A is locatedon head 350A, protrusion 363A locks into either groove of grooves 348A,349A that define a recessed surface on anterior surface 302 in a mannersimilar to protrusion on flexible bar 161A of locking element 150Alocking into either groove 148A, 149A. It should be appreciated that theinner protrusion feature may also be included on locking elements 250A,250B used with implant 200 to prevent over rotation.

Locking elements 350A, 350B are positioned through correspondingopenings in the implant. In particular, and as shown in FIG. 22B, head352B of locking element 350B is disposed in an open volume belowanterior surface 302, while shaft 356B extends through opening 381B.From the open volume to a surface of graft window 316, opening 381Bflares outward and becomes wider. In this manner, a risk of back out oflocking element is reduced as a minimum amount of force will be requiredto pull radial ridge 367A in an anterior direction through the openingwhile it is initially blocked by a surface of opening 381B that becomesnarrower closer to anterior surface 302. The opening shown in FIG. 22Band described above may also be included in implant 200.

In another aspect, the present disclosure relates to a graft clip. Inone embodiment, and as shown in FIGS. 23 and 24 , graft clip 400includes an upper grip arm 402 and a lower grip arm 404 that extend froma proximal end 411 to a distal end 412. Grip arms 402, 404 are joinedthrough connective element 406, which joins one side of the respectivegrip arms. In this manner, a space between grip arms 402, 404 isentirely open on one side, but is blocked by connective element 406 onthe side shown in FIG. 23 . An internal space between upper grip arm 402and lower grip arm 404 is sized to accommodate disposal of outer shaft11 therein. Further, inner surfaces 415, 416 on respective grip arms atproximal end 411 are rounded and sized for snap in engagement of outershaft 11 so that outer shaft 11 is securable to graft clip 400.

Each grip arm has a similar shape, though in the variant in the figures,upper grip arm 402 includes an angled portion along its length such thata space between the grip arms is greater over a portion of the length.Toward the distal end, each arm tapers toward the other, as shown inFIG. 24 . Also near distal end 412, each grip arm has a paddle that iswider than a remainder of the arm and includes a stop feature that facesoutward away from the opposing arm. Thus, upper grip arm 402 includesupper paddle 420 with upper stop 422. Upper stop 422 protrudes from asurface of upper paddle 420 with an increasing depth toward distal end412. A maximum depth of upper stop 422 defines a ridge 424. The featureof lower paddle 430 and lower stop 432 for graft clip 400 are the sameas those on upper grip arm 402.

In another aspect, the present disclosure relates to a lordoticintervertebral implant, one embodiment of which is shown in FIGS. 25-30. Unless otherwise stated, like reference numerals refer to likeelements of above-described intervertebral implant 100, but within the500-series of numbers. Surfaces 506, 508, 510, 512 of lordoticintervertebral implant 500 include a distribution of diamond shapedholes that extend through the body to an opposing side. Anterior surface502 also includes diamond shaped holes through its surface, althoughonly through part of the surface, as shown in FIGS. 25 and 28 . Theseholes give the implant a predetermined degree of porosity. Posteriorsurface 504 does not include holes, as shown in FIG. 27 . In variants,the diamond shaped holes as shown may be substituted with holes havingother shapes.

Implant 500 also includes two openings 541, 545, as shown in FIGS. 25and 28 . Opening 541 is aligned with a center axis of implant 500 andextends from anterior surface 502 to an interior surface that bordersgraft window 516. Opening 145 is aligned at an angle relative to opening541 and also extends from anterior surface 502 to the interior surface.Opening 545 is positioned such that its exit location on anteriorsurface is on a lateral side of anterior surface. As depicted, thealignment of opening 545 is less than forty five degrees relative to analignment of opening 541. However, in variations, the alignment ofopening 545 may vary. Each opening 541, 545 is defined by a threadedinner wall. With the availability of these uniquely positioned openingson the anterior surface, implant 500 is insertable into the spine withits lateral sides aligned with an insertion tool when attached viaopening 541. Implant 500 is also insertable at an angle relative to anaxis of an insertion tool when secured to the tool via opening 545. Thisprovides the user with multiple options for an approach to the spine toplace the implant in a desired orientation, which is advantageous whereaccess is limited to certain approaches.

In another embodiment, lordotic intervertebral implant 600 is shown inFIGS. 31-36 . Unless otherwise stated, like reference numerals refer tolike elements of above-described intervertebral implant 500, but withinthe 600-series of numbers. Implant 600 is taller than implant 500 andhas a greater depth to width ratio. Implant 600 includes holes on allsurfaces, including posterior surface 604. Further, in addition toopenings 641, 645 positioned in a manner similar to openings in implant500, implant 600 also includes opening 651, shown in FIG. 35 , extendingthrough lateral surface 608 and into a surface that defines graft window616. Opening 651 allows an insertion tool to be attached from thelateral side of implant 600, thereby providing another option fordirecting the insertion tool into the intervertebral space. Thus, forexample, to place implant 600 in the intervertebral space in a desiredorientation, the availability of three openings accessible from threedifferent locations on the implant surface, each at different approachangles, allows the user to direct the implant into the space from atleast three different approaches.

In another aspect, the present disclosure relates to a system forimplantation of intervertebral implants. In one embodiment, system 5includes an insertion tool 10 and drill guide 60. In other embodiments,the system may include a combination of any insertion tool and any drillguide contemplated herein. In one embodiment, a system includes aninsertion tool and a graft clip.

In another aspect, the instruments and implants contemplated herein maybe included as part of a kit. In one embodiment, a kit includes aninsertion tool, a drill guide and a graft clip. In some embodiments, akit includes two or more of any one of the aforementioned instruments.For example, a kit with multiple insertion tools may include insertiontools in any number of sizes including 10/12, 14/16, 18/20 and 22/24 mm.In other embodiments, a kit includes two or more implants. In someexamples, the implants may be the same, in others, the implants in thekit may be different or there may be groups of implants within a largerset that are the same. In other embodiments, a kit includes acombination of instruments and implants. Any number of a particularinstrument or implant may be included in these variations. It should beappreciated that the above embodiments are illustrative and that anycombination of the above embodiments may be used to form a kit.

In some embodiments, a kit includes a combination of instruments and/orimplants as described above along with other instruments or othermaterials used in spinal surgery, such as a screw driver. The kit may bevaried in many ways. For example, the various combinations of elementsof any contemplated kit may be included in a single package ordistributed among multiple packages. In other examples, the kitcontemplated herein may be accompanied by an instruction manual on howto perform one or more of the methods of using the contents of the kit.

In another aspect, the present disclosure relates to a method ofinserting an intervertebral implant into an intervertebral space in abody of a patient. In one embodiment, shown in FIGS. 37-45 , insertiontool 10 is advanced into engagement with implant 700, as shown in FIG.38 . In particular, arms 14A, 14B are advanced through opening 134 andpin 18 is advanced through opening 135. Pin 18, when inserted along witharms 14A, 14B, prevents rotation of the insertion tool relative to theimplant during use. Pin 18 also prevents forces from acting on arms 14A,14B. During advancement, the arms flex inward to fit through theopening. Once protrusions 15A, 15B of the respective arms pass throughopening 134, the arms snap outward toward their biased position, shownin FIG. 38 . During this time, and as shown in FIG. 37 , lever arm 34 ispositioned such that it is pivoted rearward and inner shaft 13 is in awithdrawn position. Once arms 14A, 14B are in the desired positionwithin implant 700 so that protrusions 15A, 15B hook onto the innersurface of the graft window, the implant is ready to be locked toinsertion instrument 10.

To lock the implant, lever arm 34 is pushed distally, i.e., away fromthe user, to overcome engagement between first groove 36 and ball detent40. As lever arm 34 is pivoted in this manner, inner shaft 13 advancesaxially within the outer shaft until it pushes in between arms 14A, 14B,as shown in FIG. 41 . Lever arm 34 is pushed further until second groove37 engages ball detent 40, locking lever arm 34 to ball detent 40 andcausing inner shaft 13 to hold in place between arms 14A, 14B. Althoughthis advancement does not substantially change the position ofprotrusions 15A, 15B hooked on the inside surface of implant 700, itprevents the arms from collapsing inward due to any forces applied tothe insertion tool. In this manner, insertion tool 10 is prevented fromaccidentally withdrawing from implant 700. A perspective view of implantsecured to insertion tool 10 is shown in FIG. 42 .

Alternatively, to lock the insertion tool to the implant, lock button 38is drawn toward the user in the direction indicated by reference numeral92 in FIG. 39 . As the button is drawn, ball detent 40 disengages fromsecond groove 37 in lever arm 34. This allows lever arm 34 to rotatefreely. Lever arm 34 is then rotated in a distal direction away from theuser as shown in FIG. 40 . The button may be used in the same manner atanother time to unlock the insertion tool from the implant. On a bottomside of handle 30 adjacent to button 20, a marking may be included toindicate a direction to actuate button in order to unlock the lever armfrom the ball detent. For example, the marking may be an arrow besidethe word “UNLOCK.” Of course, other words or symbols may also be used toprovide an indication for operation to the user.

In a subsequent step of the method, drill guide 60 is positionedproximal to an enlarged distal portion of outer shaft 11, as shown inFIG. 43 . As shown, channel 63 within drill guide 60 is sized so thatdrill guide 60 fits over outer shaft 11. Drill guide 60 is then slidaxially in a distal direction toward the attached implant 700, asindicated by reference numeral 94 in FIG. 43 . As drill guide 60 passesover button 20, button depresses so that drill guide may pass over it.Alternatively, the user may press the button down prior to advancing thedrill guide over. Pressing of the button compresses springs 22A, 22Bbeneath it allowing button downward into a space beneath it temporarilywhile load is applied. At the same time, and as shown in part in FIG. 44, rails 64A, 64B of drill guide 60 are slidably received incorresponding slots 26A, 26B on outer shaft 11. Drill guide 60 continuesto be advanced until edge 75 is distal to and no longer over button 20.Once drill guide 60 is past button 20, button 20 springs outward andreturns to its unbiased, expanded position as shown in FIGS. 44 and 45 .When drill guide 60 reaches this position, it is fully seated in andcaptured by insertion tool 10. In a distal direction, rails 64A, 64Babut ends 27A, 27B of the slots along sides of outer shaft 11 to preventfurther distal movement. In the proximal direction, drill guide 60 isprevented from backing out of insertion tool by button 20 protrudingfrom outer shaft 11 surface. Through the slidable engagement betweenrails and slots, drill guide is also prevented from disengaging in anupward direction as well. It should be appreciated that, although notshown, slot 26B is equal and directly opposite slot 26A.

With the above steps completed, the implant is ready for placement in anintervertebral space of a patient and/or for the drilling of fastenerswith a driver tool positioned through bores of drill guide intocorresponding openings in the implant. The drill guide may be removedfrom the insertion tool at any time by pressing down on button 20 andthen sliding drill guide 60 over button 20 axially in a proximaldirection.

The above method illustrates that the combination of an insertion tooland a drill guide as described is advantageous because the insertiontool may be used to insert an implant, but that it may also be used witha size specific drill guide that may be attached to the insertion tool.Further, the drill guide may be attached to the insertion tool prior toplacing the implant in the intervertebral space or after the implant isin its intended placement location in the spine.

In another aspect, fasteners in an implant are locked using lockingelements. In one embodiment, implant 100 is secured in place within anintervertebral space through the seating of fasteners 121, 124, 127 asshown in FIG. 46 into vertebral bodies adjacent to the vertebral space.The fasteners may be seated one at a time through the use of a driverelement, for example. Although fasteners with particular features areshown in the figures, it is contemplated that other fasteners may beused to secure the implant within the intervertebral space. To preservethe fasteners seated position, locking elements 150A, 150B are bothrotated in a clockwise direction to move the locking elements from afirst locked position shown in FIG. 46 to a second locked position shownin FIG. 48 . As FIG. 46 shows, in the first locked position, neitherlocking element 150A, 150B blocks any of the fasteners. However, as FIG.48 shows, in the second locked position, head 152A blocks fasteners 121,124 and head 152B blocks fasteners 124, 127. In this manner, fasteners121, 124, 127 are covered and thereby blocked from backing out ofimplant 100. The position of the locking element relative to the bodymay also be referred to as its orientation.

Details of how locking elements 150A, 150B interact with the implantstructure to move from the first locked to the second locked positionare shown in FIGS. 47 and 49 , where FIG. 47 illustrates the firstlocked position and FIG. 49 illustrates the second locked position. Withlocking element 150A referenced as illustrative, in the first lockedposition, ridge 162A of base element is located at first location 145Aon the perimeter of second recessed surface 144A, at an end of the areadefined by the second radius. On an opposite side of the base of lockingelement 150A is protrusion 163A, which is disposed in first groove 148A.When locking element 150A is rotated in a clockwise direction, flexiblebar 161A bends inward upon disengagement from first groove 148A so thatflexible bar 161A fits within second recessed surface 144A as it rotatestoward second groove 149A. Once rotation brings protrusion 163A oversecond groove 149A, flexible bar 161A expands into its neutral state andprotrusion 163A snaps into second groove 149A to establish the secondlocked position, as shown in FIG. 49 . Simultaneously, ridge 162Arotates along second radius of second recessed surface from firstlocation 145A until it approaches an end of the arc at second location146A. One function of the end surfaces abutting second recessed surface144A at the first and second locations is to prevent locking element150A from over-rotating. By way of example, if clockwise rotation oflocking element 150A were to rotate protrusion 163A past the secondgroove, further rotation would be prevented because ridge 162A isblocked from further rotation by the end surface at second location146A, as shown in FIG. 49 . The method described immediately above forimplant 100 may be performed in the same manner for implant 700.

The design of locking elements 150A-B, 750A-B is advantageous because itprovides visual, tactile and audible feedback to the user to confirmthat the locking elements are in a locked position. Visual feedback isprovided by knowledge that an observation of each locking element in ahorizontal position indicates that each locking element is locked, asshown, for example, in FIG. 48 . Further, the visualization feature ispresent even where the implant is a size other than that depicted.Tactile feedback is provided by the flexible bar as it moves from anintermediate position into either locked position, i.e., blocking thefasteners in FIG. 48 or clear of the fasteners in FIG. 46 . For example,when protrusion 163A snaps into a respective groove 149A on the anteriorsurface, the user experiences a “pop” sensation. Audible feedback isprovided through the use of a torque-limiting cam lock driver to lockthe locking element. When a locking element reaches a locked position,the lock driver breaks away from the locking element and the breakagemakes a sound. At the same time, the user senses the breakage of thelock driver, another form of tactile feedback.

The method shown in FIGS. 46-49 may also be performed with implant 200,as shown in FIGS. 50-51 and with implant 300, as shown in FIGS. 52-53 .With implant 200, FIG. 50 shows a first locked position of lockingelement 250A. In this position, both grooves 272A, 273A on head 252A areengaged with inward bumps 248A, 249A on an edge of first recessedsurface 242A. When rotated into the second locked position of FIG. 51 ,only groove 273A remains engaged to implant 200 at bump 249A. Shown inhidden lines is inner protrusion 262A, the movement of which is limitedby an outer dimension of second recess 244A to prevent over-rotation oflocking element 250A. Turning to implant 300, when locking element 350Bis disengaged from the first locked position of FIG. 52 , flexible bar361B bends inward while locking element 350B rotates in a firstdirection until protrusion 363B snaps into second groove 349B, as shownin FIG. 53 . Again, during rotation, ridge 362B under head 352B limitsover-rotation. Although not shown, in this configuration, a pair oflocking elements are rotated in opposite directions to move toward adesired position. Thus, where locking element 350B is rotated in a firstdirection to move into the locked position, locking element 350A (notshown) is rotated in a second direction opposite the first.

In yet another embodiment, the method of attaching the implant and thedrill guide to the instrument are performed together with the securementof the implant in an intervertebral disc space and locking of thelocking elements of the implant, as described above, as a single method.

In another embodiment, the method involves steps corresponding to FIGS.37 through 42 , after which the implant is advanced into anintervertebral space for implantation. In yet another embodiment,implant 700 is secured to insertion tool 10, and then graft clip 400 isattached to both. The attachment of graft clip 400 is illustrated inFIGS. 54-56 . Initially, an open side of graft clip is directed overouter shaft 11, as shown in FIG. 54 . Then, once graft clip covers outershaft, graft clip 400 is rotated about ninety degrees in acounterclockwise direction when facing away from the user at theproximal end, as indicated by reference numeral 492. The rotation snapsgraft clip 400 into place on the insertion tool 10 via the innersurfaces 415, 416 at proximal end 411. Graft clip 400 is then slid downouter shaft as indicated by reference numeral 494 until paddles 420, 430cover implant 700, as shown in FIG. 56 . The operative position of graftclip 400 relative to implant 700 shown in FIG. 56 is exemplary, thoughit is envisioned that distal end 412 of the graft clip may be positionedcloser to or further from a distal end of implant 700. The preparationof the insertion tool is now completed for use in insertion of theimplant into the spine.

In some variations, the method may include further steps of insertion ofthe tool with the graft clip attached. When inserted into a disc spaceas a complete assembly as shown in FIG. 56 , the upper and lower stops420, 430 bottom out on the bone of the vertebrae adjacent to the targetdisc space while implant 700 continues to be advanced as much asnecessary to position it in a final implant location. One advantages ofthis approach is that it minimizes dislodging of bone graft in theimplant during impaction of the implant into the disc space. The methodalso allows for access into smaller disc spaces than would otherwise bepossible. Additionally, the tapered distal ends of each arm provide animproved lead-in to the target disc space.

It should be noted that any of the devices and methods disclosed hereincan be used in conjunction with robotic technology. For example, theinsertion tool described herein can be used with robotic surgicalsystems to perform an implant insertion procedure. The insertion toolcan be manipulated with a robotic system or a robotic arm to rotate,position, and actuate the lever arm of the insertion tool during aprocedure. Further, any or all of the steps described in the methods forperforming an implant insertion or securement procedure of the presentdisclosure may be performed using a robotic system.

Although the disclosure herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent disclosure. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present disclosure as defined by the appended claims.

1. An intervertebral spacer assembly comprising: an intervertebralspacer, the intervertebral spacer comprising: a superior surfaceconfigured to engage a superior vertebral body; an inferior surfaceconfigured to engage an inferior vertebral body; a proximal surfacecomprising: a first fastener channel configured to receive a firstfastener, the first fastener channel oriented to pass through theproximal and superior surfaces of the intervertebral spacer at a firstangle; a second fastener channel configured to receive a secondfastener, the second fastener channel oriented to pass through theproximal and inferior surfaces of the intervertebral spacer at a secondangle; and a locking member channel intermediate the first and secondfastener channels, the locking member channel comprising: an inner wall;an annular ridge formed in the inner wall; a first pair of recessesformed in the inner wall; and a second pair of recesses formed in theinner wall and angularly offset from the first pair of recesses about alongitudinal axis of the locking member channel; and a locking membercomprising: a first anti-backout member; a second anti-backout member;and a collet comprising: an annular flange configured to be retained bythe annular ridge of the locking member channel in order to rotatablycouple the locking member to the intervertebral spacer; a peripheralwall; a first stop protrusion projecting from a first side of theperipheral wall; and a second stop protrusion projecting from a secondside of the peripheral wall, opposite the first stop protrusion;wherein: the locking member is rotatable within the locking memberchannel between two stable positions comprising an unlocked position anda locked position; in the unlocked position, the first and second stopprotrusions protrude into the first pair of recesses in order to retainthe locking member in the unlocked position, and the first and secondanti-backout members do not obstruct the first and second fastenerchannels; and in the locked position, the first and second stopprotrusions protrude into the second pair of recesses in order to retainthe locking member in the locked position, and the first and secondanti-backout members obstruct the first and second fastener channels inorder to prevent the first and second fasteners from backing out of thefirst and second fastener channels.
 2. The intervertebral spacerassembly of claim 1, further comprising at least one bone graft channeloriented to pass through opposing ends of the intervertebral spacer. 3.An intervertebral spacer comprising: a superior surface configured toengage a superior vertebral body; an inferior surface configured toengage an inferior vertebral body; a proximal end comprising: at leastone fastener channel configured to receive a fastener, the at least onefastener channel oriented to pass through the proximal end of theintervertebral spacer and the superior and/or inferior surface of theintervertebral spacer; and a locking member channel comprising: an innerwall; and one or more inner wall engagement features; and a lockingmember comprising: an anti-backout member; a collet retainable withinthe locking member channel; and one or more collet engagement features;wherein:  the locking member is rotatable within the locking memberchannel between an unlocked position and a locked position;  in theunlocked position, the one or more collet engagement features engage theone or more inner wall engagement features in order to retain thelocking member in the unlocked position, independently of any additionalcomponent besides the locking member and the intervertebral spacer, andthe anti-backout member does not obstruct the fastener channel; and  inthe locked position, the one or more collet engagement features engagethe one or more inner wall engagement features to retain the lockingmember in the locked position, independently of any additional componentbesides the locking member and the intervertebral spacer, and theanti-backout member obstructs the fastener channel in order to preventthe fastener from backing out of the fastener channel; wherein thecollet is compressible.
 4. The intervertebral spacer of claim 3, whereinthe proximal end of the intervertebral spacer comprises: a first stopsurface configured to prevent the locking member from rotating in afirst direction past the unlocked position; and a second stop surfaceconfigured to prevent the locking member from rotating in a seconddirection past the locked position.
 5. The intervertebral spacer ofclaim 3, further comprising at least one bone graft channel oriented topass through opposing ends of the intervertebral spacer.
 6. Theintervertebral spacer of claim 3, wherein the at least one fastenerchannel comprises: a first fastener channel configured to receive afirst fastener, the first fastener channel oriented to pass through theproximal end and the superior surface of the intervertebral spacer at afirst angle; and a second fastener channel configured to receive asecond fastener, the second fastener channel oriented to pass throughthe proximal end and the inferior surface of the intervertebral spacerat a second angle.
 7. The intervertebral spacer of claim 6, whereinlocking member further comprises a second anti-backout member such thatin the locked position, the anti-backout member obstructs the firstfastener channel and the second anti-backout member obstructs the secondfastener channel.
 8. The intervertebral spacer of claim 3, wherein thelocking member channel further comprises an annular ridge on the innerwall, the annular ridge being spaced apart from an at least one bonegraft channel oriented to pass through opposing ends of theintervertebral spacer.
 9. The intervertebral spacer of claim 8, whereinthe locking member channel extends from the proximal end to the at leastone bone graft channel.
 10. The intervertebral spacer of claim 3,wherein the one or more collet engagement features are a firstprotrusion and a second protrusion and the one or more inner wallengagement features are a first recess and a second recess.
 11. Theintervertebral spacer of claim 3, wherein the superior surface and theinferior surface include teeth.
 12. The intervertebral spacer of claim3, wherein the anti-backout member includes a drive adapted for receiptof a drive tool, a center of the drive being coaxial with an axis ofrotation of the locking member.
 13. The intervertebral spacer of claim3, wherein the collet includes a slit passing therethrough.
 14. Theintervertebral spacer of claim 13, wherein the collet further comprisesa pair of surfaces that define the slit, the surfaces being parallel toan axis of rotation of the locking member.
 15. The intervertebral spacerof claim 3, wherein the locking member further comprises an annularflange at a distal end of the collet.